Preoperative Dexmedetomidine & EC50 of Propofol (PreopDXM)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Hee-Pyoung Park, Seoul National University Hospital
ClinicalTrials.gov Identifier:
NCT02097407
First received: March 24, 2014
Last updated: NA
Last verified: March 2014
History: No changes posted
  Purpose

Dexmedetomidine is a useful anaesthetic adjuvant for general anaesthesia. In this prospective randomised study, we determined whether preoperative dexmedetomidine administration could reduce the half maximal effective concentration (EC50) of propofol for successful i-gelTM insertion without muscle relaxants.


Condition Intervention Phase
Urologic Surgery
Drug: Group C : Saline + propofol group
Drug: Group D : Dexmedetomidine + propofol group
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Supportive Care
Official Title: Preoperative Dexmedetomidine Reduces the EC50 of Propofol for Successful i-gelTM Insertion Without Muscle Relaxants

Resource links provided by NLM:


Further study details as provided by Seoul National University Hospital:

Primary Outcome Measures:
  • EC50 of propofol required for successful i-gel insertion [ Time Frame: During i-gel insertion anticipated up to 1 min ] [ Designated as safety issue: No ]
    The EC50 of propofol for successful i-gel insertion was determined by a modification of Dixon's up-and-down method. The response of each patient determined the effect-site propofol concentration for the next patient. If the response was deemed 'successful', the next target concentration of propofol was decreased by 0.5 µg mL-1. If the response was deemed a 'failure', the target concentration was increased by the same dose. The process was repeated until the sixth crossover point (success/failure) was obtained.


Secondary Outcome Measures:
  • the total dose of propofol infused before i-gel insertion [ Time Frame: During i-gel insertion time anticipated upto 1min ] [ Designated as safety issue: No ]
    The total amount of propofol infused before i-gel insertion was noted. The insertion time, defined as the time from picking up the i-gel until the initiation of mechanical ventilation.

  • the presence/severity of airway trauma after i-gel insertion [ Time Frame: At the time point of removing the i-gel from patient's mouth ] [ Designated as safety issue: No ]
    After removing the i-gel, airway trauma (defined as any blood staining on the device) was recorded.


Enrollment: 37
Study Start Date: May 2012
Study Completion Date: August 2012
Primary Completion Date: August 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Group D : Dexmedetomidine + propofol group
In Group D, DEX (1 µg kg-1) was intravenously loaded for 10 min before induction of anaesthesia.
Drug: Group D : Dexmedetomidine + propofol group

All patients were pre-oxygenated with 100% oxygen with spontaneous breathing for 3 min before the end of loading of dexmedetomidine. Anaesthesia was induced with predetermined effect-site propofol concentrations using a target-controlled infusion device (Orchestra; Fresenius-Vial, Brezins, France). The first patient in Group D received an effect-site propofol concentration of 3 and 5 µg mL-1, respectively, over 5 min.

After equilibration of the plasma and effect-site propofol concentrations, i-gel (size 4 for patients weighing 50-90 kg, size 3 for patients weighing 30-50 kg) was inserted using the standard technique by a single anaesthesiologist staff member with expertise in i-gel insertion and who entered the operating room immediately before i-gel insertion to blind him to the group assignment.

Placebo Comparator: Group C : Saline + propofol group
In Group C, 0.9% of normal saline (1 µg kg-1) was loaded 10 min before induction of anaeshtesia.
Drug: Group C : Saline + propofol group

All patients were pre-oxygenated with 100% oxygen with spontaneous breathing for 3 min before the end of loading of normal saline. Anaesthesia was induced with predetermined effect-site propofol concentrations using a target-controlled infusion device (Orchestra; Fresenius-Vial, Brezins, France). The first patient in Group C received an effect-site propofol concentration of 3 and 5 µg mL-1, respectively, over 5 min.

After equilibration of the plasma and effect-site propofol concentrations, i-gel (size 4 for patients weighing 50-90 kg, size 3 for patients weighing 30-50 kg) was inserted using the standard technique by a single anaesthesiologist staff member with expertise in i-gel insertion and who entered the operating room immediately before i-gel insertion to blind him to the group assignment


Detailed Description:

Propofol is a useful induction agent for LMA insertion without muscle relaxants because it profoundly inhibits pharyngeal and laryngeal reactivity. A previous report showed that the effect-site concentration of propofol for successful classic LMA insertion in 50% of adults (EC50) without muscle relaxants in healthy male patients was 8.72 (0.55) µg ml-1. The EC50 of propofol may be dependent on the type of LMA used. A previous study comparing the EC50 of the propofol concentration between classic and proseal LMA insertions demonstrated that the EC50 of propofol needed for proseal LMA insertion was 35% greater than that needed for classic LMA insertion. Unfortunately, no investigation has been performed to determine the EC50 of the propofol concentration required for i-gel insertion without muscle relaxants.

Dexmedetomidine (DEX), a selective alpha-2 agonist, has sympatholytic, sedative, and analgesic properties. Such beneficial characteristics make DEX a useful anaesthetic adjuvant for general anaesthesia. Many reports have revealed the beneficial effects of DEX in terms of reducing intraoperative anaesthetic requirements, postoperative analgesic demand, and increased haemodynamic responses to noxious stimuli such as endotracheal intubation. A previous investigation showed that preoperative clonidine, an alpha-2 agonist, decreased the EC50 required for LMA insertion.

We hypothesised that preoperative DEX administration can reduce the propofol concentration required for i-gel insertion. In this study, we compared the EC50 of propofol needed for successful i-gel insertion without muscle relaxants between DEX and placebo groups

  Eligibility

Ages Eligible for Study:   20 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • ASA physical status I-II patients who were 20-65 years old and scheduled for general anaesthesia for urologic surgery

Exclusion Criteria:

  • Patients with an allergy to alpha-2 adrenergic agonists or propofol
  • Patients who anticipated difficult airway (cervical spinal disease, Mallampati score of III or IV, a mouth opening of <2.5 cm, and/or body mass index of >30 kg m-2), unstable teeth
  • Patients with bradycardia of <50 beats/min, heart block greater than first degree, severe cardiorespiratory dysfunction
  • Patients with symptoms of upper respiratory infection
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT02097407

Locations
Korea, Republic of
Seoul National University of Hospital
Seoul, Korea, Republic of, 110-799
Sponsors and Collaborators
Seoul National University Hospital
Investigators
Study Director: Hee Pyung Park, MD PhD Professor
Principal Investigator: Young Cheol Kim, Md PhD Professor
  More Information

No publications provided

Responsible Party: Hee-Pyoung Park, Associate Professor, Seoul National University Hospital
ClinicalTrials.gov Identifier: NCT02097407     History of Changes
Other Study ID Numbers: PreopDXM_PPF
Study First Received: March 24, 2014
Last Updated: March 24, 2014
Health Authority: Korea: Food and Drug Administration

Additional relevant MeSH terms:
Propofol
Dexmedetomidine
Hypnotics and Sedatives
Central Nervous System Depressants
Physiological Effects of Drugs
Pharmacologic Actions
Central Nervous System Agents
Therapeutic Uses
Anesthetics, Intravenous
Anesthetics, General
Anesthetics
Analgesics, Non-Narcotic
Analgesics
Sensory System Agents
Peripheral Nervous System Agents
Adrenergic alpha-2 Receptor Agonists
Adrenergic alpha-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action

ClinicalTrials.gov processed this record on October 02, 2014